Polyetherimide ester elastomers comprised of the reaction products of (a) a low molecular weight diol, (b) a dicarboxylic acid, (c) a high molecular weight poly(oxy alkylene)diamine, and (d) a tricarboxylic acid or its derivative are known and are described in U.S. Pat. Nos. 4,544,734 and 4,556,705 to McCready and in U.S. Pat. Nos. 4,556,688 to McCready et al. These polyetherimide esters exhibit excellent stress-strain properties, low tensile set, high melting temperatures and/or excellent strength/toughness characteristics as well as superior flexibility, which properties render said polyetherimide esters specially suitable for molding and extrusion applications.
Aromatic carbonate polymers are well known, commercially available materials having a variety of applications in the plastics art. Generally speaking, aromatic polycarbonate resins offer a high resistance to the attack of mineral acids, may be easily molded, and are strain resistant. In addition, such polymers have a high tensile and impact strength, a high heat resistance, and dimensional stability.
It has now been discovered that blends of a polyetherimide ester elastomer and a polycarbonate resin result in compositions which have excellent physical properties, including impact resistance.
In particular, blends of polyetherimide ester resins and polycarbonate resins result in compositions that have markedly superior tensile strength compared to unmodified polyetherimide ester resins.